Viscous hydrocarbon oil



' vide new and improved lubricating oils.

Patented Apr. 14, 1942 STATES 2,279,560 VISCOUS HYDROCARBON on.

No Drawing. Application May 8, 1940, Serial No. 334,066

Claims.

This invention relates to improved viscous hydrocarbon oils and more particularly to improved lubricating oils and to a process for improving lubricating oils.

The main function of a lubricating'oil consists in prevention of seizure of parts, which present day conditions, particularly in the automotive field, higher speeds, temperatures, and pressures are continually being used with the resultant need for lubricants which will have the necessary film strength to maintain separation of the moving parts, reduce wear, and prevent actual seizure. This may be accomplished by adding to the oil a component which will improve its film strength and load-bearing capacity. A number of materials have been suggested for this purpose, such as esters of long-chain acids, chlorinated hydrocarbons and sulfurized fatty oils. These materials may improve film strength'to a certain degree but quite oftenhave objectionable effects along other lines, such as impairing the oxidation resistance of the oil or causing corrosion of bearing metals.

Under conditions of high temperature and exposure to oxygen or air, lubricating oils tend to form corrosive products or sludge which may function adversely on the lubricating efliciency through deposition in oil lines, plugging of oil ducts, formation of deposits on bearing surfaces, or through corrosive action on the engine metals. Although a number of compounds have been suggested for addition to lubricating oils, such as naphthols and secondary or tertiary amines, many of these materials are inefiective at high temperatures or lose their effectiveness in the presence of catalytic metals such as iron or copper.

It is an object of the present invention to improve the properties of viscous hydrocarbon oils. Another object is to improve the stability of viscous hydrocarbon oils. A further object is to improve the film strength and stability of lubricating oils. A still further object is to pro- Other obtained from the various base crude oils.

objects are to provide new compositions of mat-' Still other objects ter and to advance the art. will appear hereinafter.

The above and other may be accomplished in accordance with my invention which comprises incorporating, in a viscous hydrocarbon oil, a small proportion of an organic hydroxamic acid compound of the group of organic hydroxamic acids, organic sulfonhydroxamic acids and the carboxylic acid esters and ethers of said acids. By the addition of such hydroxamic acid compounds to viscous hydrocarbonoils, the stability of such oils against deterioration normally caused by oxygen, heat, and the catalytic influence of metals is greatly improved. When the viscous hydrocarbon oilis a lubricating oil which is to be employed for the lubrication of metallic bearing surfaces, it will be found that the hydroxamic acid compounds added in accordance with my invention improve the film strength of such oils.

By the term viscous oils, I mean those which have a viscosity of at least 35 seconds Saybolt at F., and intend to include Diesel oils, furnace oils, transformer oils and greases, as well as the ordinary lubricating oils. The oils may be solvent extracted or conventionally refined oils The oils may be employed in greases or may be specially compounded oils such as those containing fish oils, lard oil or castor oil. Preferably the oils are petroleum lubricating oils, that is, lubricating oils derived from petroleum. The improved oils of my invention are preferably employed as lubricants particularly in the lubrication of internal combustion engines, of bearings subjected to high speeds and high pressures, of gears of the hypoid, spiral or bevel types, of railroad rolling stock, and of marine engines. The improved oils of my invention may also be employed as protective coatings for steel and other metal surfaces.

By the term organic hydroxamic acid), I mean a compound having the formula wherein R is an organic group having a carbon atom thereof directly bonded to the carbon of the C group- By the term organic sulfonhydroxamic acid," I mean a compound having the formula.

wherein R is an organic group having a carbon atom thereof directly bonded to-the sulfur of the L group By the term "carboxylic acid esters" of such acids, I mean compounds in which the OH of the NHOH group of the hydroxamic acid or sulfonhydroxamic acid has been esterifled with a carboxylic acid. By ethers" of such acids, 1 mean compounds in which the hydrogen of the OH group in the NHOH radical of the hydroxamic or sulfonhydroxamic acid has been replaced by a carbon of an organic group.

While any of the organic hydroxamic acid compounds may be employed, it will generally be preferred that the compounds be devoid of acid substituents. By the term acid substituents, I mean substituted groups which are acidic in reaction, such as sulfonic acid, carboxylic acid and the like, which would tend to make the compounds acidic in nature, but do intend to include within such term phenolic or alcoholic hyticularly preferred. Of the organic hydroxamic acids, the most desirable will be: those which, ex cept for 1 to 2 hydroxamic or v i --C-NHOH groups, consist of carbon and hydrogen and of .these the aliphatic hydroxamic acids, and especially those containing at least carbon atoms, will be preferred. For some purposes, particularly for the stabilization of oils, the dihydroxamic acids and their esters will be preferred. For other purposes, and particularly for producing high film strength, the organic sulfonhydroxamic acids, and particularly the aryl sulfonhydroxamic acids of the benzene series-con:

taining one or more alkyl groups on the ring, will be particularly desirable.

Amongst the compounds of my invention, which I have found to be very satisfactory for my purpose, the following are particularly effective:

Laurohydroxamic acid 0 C1 Hll -C.--NH0 H Sebacodihydroxamic acid 0 nonN-r rcnor-rLNnou Diacetyl ester of adipodihydroxamic acid 0 omit-o-rr-ii-wrmlii-N-0- H -om t Dibenzyl' ether of adipodil iydroxamic acid.

p -Toluenesulfonhydroxamic acid CH|-C|Ha S:-NHOH p-Amylbenzenesulfonhydroxamic acid Oleohydroxamic acid Cr1Ha( ,NHOH Palmitohydroxamic acid 0 c mr-g-mion Salicylhydroxamic acid cnnu-o-cm-t i-mrou p-tert-Amylphenoxyacetohydroxamic acid 0 clnn-cdii-o-mnr- -Nr ron N-dibutylaminoacetohydroxamic acid,

(CCHQ)INCHI- 'NHO H Dodecane- 1-mercaptosuccinodihydroxamic acid Cyclohexylmercaptosuccinodlhydroxamic acid o Beta-phenyladipodihydroxamic acid ll 3 acid Meta-phenylenedioxyacetohydroxamic Stearohydroxamic acid ll uHu-C-NHOH The organic hydroxamic acid compounds of my invention may be incorporated in the oil by various methods such as by simple mixing and heating where their solubility characteristics permit, or by grinding or passage through a colloid mill as desired. Those of my compounds which contain 6 or more carbon atoms are generally suillciently soluble so that they may be incorporated by simple mixing and heating. Those having a lower number of carbon atoms are less soluble and would generally require grinding or the like, or the use of a blending agent in order to disperse them in the oil satisfactorily. The concentration of the compounds in the oil will be determined largely by the effect 1 desired, but in general will lie between about 0.1% and about 5%. The preferred concentration will generally be between about 0.2% and about 1.0%. 'Where it is desiredto stabilize the oils against the catalytic effects of metals only, the concentrations of the compound employed may run to 0.01% or even lower depending upon the concentration of metal whose catalytic eifect is to be inhibited.

The preparation of hydroxam'ic acids, their esters, and ethers, is described in the literature and follows well-known chemical methods. The preparation of a few representative compounds is given in the following examples, in which the quantities are given as parts by weight.

EXAMPLE I Preparation of. laurohydrozamic acid 27 parts of sodium methylate, contained in 155 parts 'of methanol solution, was poured into a solution of 35 parts by weight of hydroxylamine hydrochloride in 239 parts of methanol. The

sodium chloride was removed and '106 parts of methyl laurate added to the filtrate. After these solutions were thoroughly mixed, an additional 155 parts of the sodium methylate solution was introduced and the mixture allowed to stand at room temperature. After standing 20 hours, the solution was acidified with dilute acetic acid to precipitate'the hydroxamic acid. Recrystallization from ethyl acetate gave'98 parts of lamehydroxamic acid, melting at 95 C. N (calculated) 6.51%, ,N (found) 6.70%.

Preparation of sebacodlhydromm g A reaction mixture, comprising a methanol solution of diethyl 'sebacate (258 parts), hydroxylamine (72.6 parts), and sodium methylate (108 parts), was allowed to stand at 30? C. for two days. A stream of dry carbon dioxide gas .was thenpassed through this solution until precipitation of sodium carbonate ceased. The

. bacodihydroxamic acid, which was a white solid melting with decomposition at 164 C. N (found), 11.88%: N (calculated). 12.07%.

Exams: III

Preparation of diacetul ester of adipodihydroz- I amic acid added with vigorous stirring. Themixture was stirred 15 hours and then refluxed for two hours. After cooling, itwas filtered and the solid reshdue recrystallized from absolute ethyl alcohol.

A yield of 16 parts of white product was obtained, M. P. 177.5 C.

, ExAMPLs IV Preparation of dibenzylether of adipodihydroztamic acid Twenty-five parts of adipodihydroxainic acid and 39.5 parts of benzyl chloride were'distilled into 53.5 parts of methyl alcohol in which 7.2 parts by. weight of sodium-had been dissolved. The mixture was refluxed hours, diluted with water, and filtered. Thesolid residue, after crystallization from absolute ethyl alcohol, was white, melted at 137 C., and contained 8.13% nitrogen, compared to a calculated value of 7.87%.

EXAMPLE V Preparation of p-toluene sulfonhydrozamic acid To a solution of 130 parts of hydroxylamine hydrochloride in 400 parts of methanol was added an equivalent amount of sodium methylate in methanol solution followed by parts of p-toluenesulfonyl chloride in 560 parts of methanol. After evaporation of the solvent, the residue was extracted with ether. Repeated recrystallization of the ether-soluble portion-from water gave a 10% yield of p-toluenesulfonhydroxamic acid melting at 134 C. Analysis: calcd. for C7H903NSI S, 17.12%; found: 8 17.24%. This melting point is somewhat lower than the one recorded in the literature, namely, 148 C.

The eifect of these compounds, on the film' brass pin. in the following table, the jaw me at point of seizure is given in pounds for the various compounds.

TABLE I Cornell film strength tests (Using a naphthenic base S.A.E. 30 oil) Concen- Load at Compound tration seizure Pounds None-control 750 p-Toluonesulfonhydroxamic acid. 0.5 1,125 p-Amylbenzensulionhydroxamic no 0. 5 875 Oleohydroxamic acid 0. 5 1, 125 Do 1.0 1, 250 Hydroxamlc acids from coconut oil acidsl- 1.0 900 Laurohydroxarnic acid l. I) 950 Palmitohydroxamic acid. 1. 850 Saiicylhydroxamic acid 1.0 4, 500+ Sebacodihydroxamic acid- 0.5 1,325 Adi ihydroxamic acid 0. 1, 000 D ecyioxyacetohydroxamic acid (R5 1,150 p-tert-Amylphencxyacctohydroxamic acid. 0.5 l, 125 N-dibutylaminoacetohydroxamic acid... 0. 5 960 Dodccanel mercaptosuccinodihydroxamic aci O. 5 1, 100 Cyclohcxylmeroaptosuccinodihydroxamic acid 0.5 900 Beta-phenyladipodihydroxamic acid 0.5 l 850 Meta-phenylenedioxyacetohydroxamic acid. 0; 5 950 8(9) -para-Hydroxyphenylstearohydroxamrc acid 0.5 900 Dibenzyl ether of adipodihydroxamic acid. 0. 5 875 of coconut oil acids obtained by hydrolysis of coconut oil.

The Almen machine has been described in Oil and Gas Joumal,' 30, 109 .(1931) and is well known in the industry. Data obtained on this machine are given in Table II.

TABLE II Almen film strength tests (Using an S.A.E. 30 oil of Mid Continent origin) This is the mixturl of hydroxamic acids derived from the mixture of naphthcnic acids obtained from petroleum.

In addition to improving film strength, the compounds function as stabilizers inthe oil to prevent deterioration of color under oxidizing conditions and in the presence of iron. This beneflcialbehavior was demonstrated in the following manner: grams or a naphthenic base S. A. E.- oil was placed in a 50 cc. Pyrex beaker open to the air at 150 C. for six hours. A piece of autobody steel "x was immersed in the oil during the heating period. Color changes were measured on a Duboscq colorimeter, using the unheated original oil as a standard. From these measurements Color Inhibition was calculated. These data are given in Table III.

"' mit seizure, is indicated either by the development of a squear' or by the shearing oi the TABLI: III Color stabilizing action of hydroxamic acids Concen- Color ompmmd tration inhibition Per cent by weight Per cent None-control 0 Lam-oh droxamic acid. 0.2 63 Oleohy xamic acid 0.2 Sebacodihydroxamlc acid 0.2 37 Diacetyl ester of adipodihydroxamic acid 0. 2 80 Dibenzyl ether of adipodihydroxamic acid 0. 2 56 The efiect of this class of compounds on the resistance of lubricating oils to the formation of sludge and degradation products caused by oxidation was determined in the following manner: 20 grams of a parafiin base S. A. E.-20 oil was placed in a 50 cc. beaker, a small piece x i of steel added and the outfit heated in air to a predetermined temperature by immersion in an oil bath. Sludgewas determined by diluting 10 grams of oil to cc. volume with special naphtha, chilling at 0 C, for three hours,

followed by filtering and weighing the precipitated sludge. The data obtained are. given in Table IV.

TABLE IV Sludge formation in oils containing hydroxamic i acids Temp. Len th Compound Cone. attest g Sludge Per cenlttbu C we: None-control 'ga figl l Laurohydroxamic acid... 0. 5 170 70 32 2 None-control Sebacodihydroxamic acid 0.5 190 $3 I None-control 1 Oleohydroxamic acid- 0. 5 1% 3i It will be noted that the above examples and tests are given for illustration purposes only. It will be readily apparent to those skilled in the art that many variations and modification can be made, particularly in the compounds empioyed, the processes .of making them, the proportions added to the oils and the conditions of use, without departing from the spirit and scope of my invention, which I intend to claim broadly as in the appended claims. For example,'other organic hydroxamic acid compounds which I have found to be satisfactory for my purpose are:

Naphthalodihydroxamic acid H O HORN-C i i-Nnou Phenylamino'acetohydroxamic ovarian-o rn-ii-Nnon Acetohydroxamic acid om-ii-mron Butyrohydroxamic acid cim-g-Naori Butylmercaptoacetohydroxamic acid CriIrS-CHQ-PJ-NHOH Lauroyl ester of acetohydroxamic acid Isobutyl ether of adipodihydroxamlc acid Phenoxyethyl ether oi propionohydroxamic acid Beta-naphthyloxyacetohydroxamic acid II 0-0 Hr-C-NH O H o-Methoxybenzohydroxamic acid ll C-NHOH OCH:

Acids (monobosic) Acids (dibesic) Acetic Snceinlc Prcpionio Melanie Bntyrio Oxal Valerie Beta-methylaglipic Cep'rylie Alpha-ethyleuipio Nonylic Beta-isopropyladi 0 Comic Beta-tcrt-butyled pie Undecylic Beta-tert-emyladipic Tridetylic Betshenyladiplc Myristlo Betap-hydroxyphenynadipic Pentedeoyiic Beta p-nie tophenghadipic Margarlc Betanltrorfienyba ipio Nonoe lic Be c-rnethoryphenyDadipic Arachi ic Beta-(p-nitrophenybadlpic Cerotio '-ketopimelio Bntylmemaptoacetio G-keto-nndecanedioic-Lll Isoprc yloxyaoetic Dodecenedioio-Lm Phony oecetic Dlcyclohexanone hotel of muclc Dodeoyleminoacetic Pimelic lzaminoeteeric Snberic 12-ketoateario Aeeho lz-hgdroxystearic Hexahydrotorphtha .alpg-ethyiaminobntync Naphthalene-l dimrboxylrc Alphe-hydroxyvaleric Dilgdronapht e-1,4-diearboxy c Alpha-chlorosteario Phenylmerca tomalonic 2,4-dinitrophenyloxyaoetic alglli a-pen me-mcmptosuo- 7 Cyciohawloxyaoetio Alpha-pentadecyloxy-s-euminic bota-Naphthyloxyacetic o-Meth benz oio p-Etlmfi o puty ereepto)benzoic opmyhnsm )benzoic o in: laminobenzoie m-(Dibu ie Diohlomrlo N ph nllalvibgxyliq In any of the hydroxamic acids, suitable esters and ethers may be used in which the ester or other radical may he as follows:

Ester radicals Ether radicals Amtyl Phenyl Propionyl Ethyl Butyr I Propyl Capry yl Butyl Napht enyl Isobutyl Lauroyl Cyclohexyl Oleyl splithyl (alpha or beta) Bonzoyl Phenylothyl Cinnamyi Ethoxyethgl Methecrylyl Phenoxyet yl Mixtures of hydroxamic acids may be used,

such as those prepared from mixed acids obtained by saponification of vegetable or animal oils, by oxidation of petroleum hydrocarbons, by oxidation of parafiin wax, or by oxidation of alcohols produced during hydrogenation of carbon oxides.

The organic hydroxamic compounds of my invention may be employed in conjunction with other agents, added to the oils for various purposes, such as, fatty acid esters, organic-phos phites, organic phosphates, halogenated aro-' of organic hydroxamic acids.

2. A composition comprising a major propor tion of a viscous hydrocarbon oil having incorporated therein a small proportion of an organic sulfonhydroxamic acid devoid of acid substituents. v

3. A composition comprising a major propor= tion of a viscous hydrocarbon oil having incor- 'porated therein a small proportion of an aromatic sulfonhydroxamic acid devoid of acid suhstituents.

a. A composition comprising a major proportion of a viscous hydrocarbon oil having inconporated therein a small proportion of an aryl sulfonhydroxamic acid of the benzene series.

5. A composition comprising a major proportion of a viscous hydrocarbon oil having incor= porated therein a small proportion of p-toluenesulfonhydroxamic acid.

mm A. DIE'I'RICH. 

